Waterproofing fibrous and other materials



Patented Jul 10, 1934 UNITED STATES PATENT OFFICE Q WATERPROOFING MAFIBBOUS AND OTHER TEBIALS Judson A. De Cew, Mount Vernon, N. Y.

20 Claim.

the fibers and filling material thereof either neu-- tral or alkaline.

Rosin sized paper has always been made with the fibers thereofacidified. That is, the present processes of engine sizing where thesizing ingredients are mixed with the pulp, some form of sodium resinateand sulfate of alumina are always used and unless suiiicient of thesulfate of alumina (alum) is used to acidify the fiber, as well as thesodium resinate, no sizing effect is obtained. The amount of alum usedvaries from 1% to 5% of the dry weight of the fiber. One part of alumwill coagulate five parts of sodium resinate but before any sizingeffect is obtained, the sodium resinate must be completely decomposedand all soda removed from combination with the resin. In order tocomplete this reaction, about 1% to 2 parts of alum are required for onepart of sodium resinate which produces an acid condition represented bya pH of 4 to 5, and this acid condition must exist a suificient lengthof time to complete the reaction.

This acid condition is required because sodium resinate is distinctlyalkaline .and when mixed with a cellulose fiber, the soda thereof isabsorbed by the :ellulose and held with such affinity that it is remived with difficulty. This fact explains why the proportions of alum andsodium resinate used in the known practice of paper sizing, are quitevariable and the excessive amount of alum generally required issufiicient to produce aninjurious effect upon the strength and permanency of the paper. Further, as the chemical reaction between sodiumresinate and sulfate of alumina varies greatly under differentconditions, there is very little uniformity in the sizing resultsobtained by the use of these ingredients. Accordingly, one object of myinvention is to devise a process of paper sizing wherein neither alumnor sodium resinate is required to be used.

The amount of acidity required for sizing paper with sodium resinate issuch that if any filling material is used that is of the type containingcarbonates as are sometimes found in clay or talc, it is necessary toconvert all of the carbonates into sulfates by treatment with alumbefore the paper can be sized because as long as any carbonates arepresent, the fibers cannot be acidified, In the presence of carbonates,the maximum-acidity that can be produced is represented by a pH of 6.5and this acidity is due to the acid reaction resulting from the presenceof carbon dioxide in solution. Even in the diluted condition of thepaper stock at the wet end of a paper machine, a pH of 5 cannot beobtained with alum in the presence of a carbonate.

Yet in recent years, many large manufacturers of book paper have usedcalcium carbonate as a loading material to the extent of 20% of theweight of the paper. It is impossible to acidify such papers and theyare always unsized when a sodium resinate size is attempted to be usedthereon. Such paper may be given a waterproofing effect by the use ofwax emulsions, when effect is not produced by a chemical reaction as insizing, but by the fusibility of the wax particles. Wax is awater-resistant lubricant but as it does not function as a binding agentlike rosin, it is not a proper substitute for rosin in paper making. So,regardless of all methods that have been previously proposed for makinga sized paper containing an alkaline filler and a size containing sodiumresinate, it is not yet possible to produce a sized paper using theseingredients because both the sodium resinate and the alkaline cellulosemust be treated with an acid concentration that is impossible to obtainin the presence of a carbonate.

Therefore, another object of my invention is to devise a method ofsizing whereby there can be sized, any papers that are loaded withfilling materials containing carbonates such as calcium or magnesiumcarbonate, and also any paper making fibers that contain free lime suchas are found in straw pulp. Also whereby paper can be sized in thepresence of hard water containing carbonates without first having toacidify all of the water with alum.

So one feature of this invention is the discovery that if a size is madewith ammonia as the base for saponification, paper can be sizedtherewith without being acidified, because the ammonia is volatile andcan be entirely removed either by hot or cold drying, which leaves thepaper neutral so far as this alkali is concerned.

Another feature of my discovery is that when 100 an ammonia soap is usedfor sizing paper, it is not necessary to acidify either the paper makingfibers or the soap, because the ammonia absorbed by the cellulose willbe removed without chemical treatment upon drying of the paper, and all105 alkalinity disappears from both the size and the paper fibers.Another feature of this process is that it can be used to size any paperfilling materials better than it is possible to do with any combinationof sodium resinate and alum.

Therefore, whereas the current methods of coagulating sodium resinateproduces first, a precipitate containing a non-volatile alkali andrequires the reaction with further alum to acidify it, by the practiceof this invention, it is found that the coagulate of ammonium resinateand aluminum hydrate does not require to be acidified by alum to producea sized paper. So this invention comprises a. new chemical reaction insizing that is distinct from prior processes which involved carrying outthe sizing operation in two steps; first, by coagulating the size; andsecond, by acidifying the basic precipitate with alum. The process ofsizing of this invention not only overcomes the many difficulties foundin sizing due to alkaline waters and fillers, but it makes possible theproduction of much stronger and more permanent papers than those thatare acid ified in the usual manner with alum to a pH of from 4 to 5.

In carrying out this process, there is first produced in the paper stockan alkaline precipitate consisting of hydrate of alumina and resinhydrate resulting from the reaction between ammonium resinate andalumina. After drying, the alkalinity disappears whereupon the papertreated therewith becomes neutral and sized. In the practice of thisprocess, I prefer to use a resinate of ammonia, although any otherammonia soap may be compounded with this, if desired. The rosin,however, has a hardening action on the paper and is found preferable toall other materials, as the essential sizing ingredient.

The ammonia size may be made from rosin or any other saponifiablewater-insoluble material, such as stearic acid, or similar product. Theammonia size may be added to the pulp fibers in any usual manner and itcan be coagulated with an aluminum hydrate which may be added in thefreshly precipitated form, or be produced from the reaction between alumand free ammonia or other alkali present in the paper stock.

An example of the method of operation of this process is as follows:

One thousand pounds of pulp fiber dry weight is mixed in an ordinarypaper mill beater with about twenty thousand pounds of water. To this isadded about three hundred pounds of alkaline filler such as CaCOa, 15pounds of ammonium resinate (dry weight) is then added in the form of anaqueous solution containing 500 pounds of water. 15 pounds of alum arethen added, which immediately reacts with the carbonate to formtheoretically 3 pounds of precipitated alumina A1203. Instead of addingthis alum to the beater, the alum solution may first be neutralized withammonia or other alkali, and the precipitated alumina added to thebeater with the size. The hydrated aluminum oxide A120: will combine inthe beater with the ammonium resinate to form a compound which coats thefibers in the beater and which will size the paper when the pulp isried.

Another method of operation is as follows:

The carbonate filler, or other filling material, is mixed with water ina tank to a concentration of about'20% solids to which mixture is'addedan aqueous solution containing ammonium resinate to the extent of aboutone pound of the dry resinate to one hundred pounds of filler. To thismay be added one pound of alum to each one hundred pounds of filler.along with sufllcient ammonia or other alkali to neutralize it andprecipitate the alumina.

This separately treated filling material con- 4 ate of alumina, but ittaining said sizing ingredients may be added to the paper stock in thebeater, in the Jordan chest, in the machine chest, or at the wet end ofthe paper machine. This treatment produces a paper containingindividually sized filler particles, that is, each particle thereof iscoated individually with size. The paper stock in the beater may besized by the use of ammonium resinate and alumina. If this is done, theresult is a paper with fibers and filler particles individually sizedwith the same sizing materials. Or the paper stock may be first sizedwith any sodium resinate and suflicient alum to acidify the fibers,whereupon and later, the ammonia sized filler material is added theretoin the beater, machine chest, jordan, and so forth, whereby a. paper isproduced. having its fibers individually sized by the use of sodiumresinate while its filler particles are individually sized with ammoniumresinate and alumina. Since the ammonium resinateis somewhat moreexpensive than sodium resinate, this latter procedure offers some savingin cost over treating both fibers and filler with ammonium resinate.

In general, in the final mixture of paper fibers and filling material,there must be no alkalinity derived from soda. There will be none in themixture resulting from the practice of this invention because anyalkalinity produced by the ammonium resinate disappears on drying of thepaper. This produces a neutral and sized paper.

With the present processes using sodium resinate, it is not possible tofully size a heavily loaded paper containing from 20% to 30% filler evenif the filler is not alkaline. By the use of my process, however, anykind of filling material can be sized. In order that ammonium resinatemay properly function asa sizing material there should be always presentenough excess ammonia or other alkali, toform suiiicien't alumina A1203,when reacting with alum to form a resinis immaterial how this ammoniumhydrate is produced.

I have also discovered that the chemical precipitate formed from ammoniaresinate and aluminum hydrate will waterproof other alkaline materialssuch as Portland cement and other cements which contain free lime orcarbonates, whereas sodium resinate and alum have no waterproofingeffect thereon, and the use of alum thereon would be more'destructive tothe useful properties of such materials.

It will thus be seen that this invention discloses a practical method ofactually sizing a paper containing an alkaline filler, by means of achemical precipitate and that it also teaches how to size a straw pulpwith-out washing the free lime therefrom. The simplicity of this processeliminates most of the difficulties in sizing heretofore due to thevariable reactions that take place between sodium resinate. and sulfateof alumina.

I claim:

1. A waterproofing material comprising the precipitate formed by thechemical reaction between an ammonium soap and aluminum hydrate.

2. A waterproofing material comprising resinate of alumina formed byprecipitating ammonium resinate with approximately its combining weightof precipitated alumina (A1201).

3. A sized, filled paper comprising a fibrous material, alkaline filler,rosin, and alumina derived from ammonium resinate and aluminum hydrate,

4. A non-acid sized paper product comprising fibrous material, rosin,and alumina derived from ammonium resinate and aluminum hydrate.

5. An alkaline sized paper product comprising a fibrous material, freelime, rosin, and alumina derived from ammonium resinate and aluminumhydrate.

6. A waterproof, calcareous cement comprising cementing material, rosin,and alumina derived from ammonium resinate and aluminum hydrate.

'l. A sized filled paper comprising fibers sized with sodiumresinate andfiller particles sized by the use of ammonium resinate.

8. A sized filled paper comprising individually sized filler particlessized with ammonium resinate.

9. In a method of manufacturing sized paper, the step of adding to thepaper mix from which said paper is to be made, ammonium resinate andhydrate of alumina.

10. In a method of manufacturing sized paper filled with alkalinefiller, the step of adding to the mixture of paper stock and filler fromwhich the paper is to be made, an ammonia soap and hydrate of alumina.

11. In a method of manufacturing sized paper filled with alkalinefiller, the addition to the paper stock from which the paper is to bemade, of ammonium resinate and hydrate of alumina.

12. In a method of manufacturing a sized filled paper, the steps ofadding to the paper stock from which the paper is to be made, an ammoniasoap, and coagulating said soap with the product of the reaction betweensaid carbonate and sulfate of alumina.

13. The method of manufacturing a sized paper which includes theaddition to the paper stock from which the paper is to be made, ofammonium resinate, a carbonate filler, and sulfate of alumina.

14. The method of making a non-acidified sized paper, which includes theaddition to the paper stock from which the paper is to be made, ofammonium resinate, and sufficient hydrate of alumina to form aluminumresinate.

15. The method of waterproofing a filling material containingcarbonates, which comprises incorporating into the wet mix a solution ofan ammonia soap, and coagulating this soap with a colloidal precipitateof hydrate of alumina.

16. The method of paper making which comprises separately sizing theparticles of the filler with a precipitate formed from ammoniumresinate, sizing the paper fibers, mixing the fibers and filler, andforming into paper.

17. The method of paper making which includes the steps of producing inthe paper stock an alkaline precipitate comprising hydrate of aluminaand resin hydrate, and then drying the so treated paper stock to producea sized neutral paper.

18. The method of making a filled paper which comprises the step ofincorporating into the filler before adding it to the paper stock, anammonia soap and later bringing about coagulation thereof in a beater.

19. The method of waterproofing a calcareous cementing material whichcomprises the addition to the wet mass, a solution of an ammonia soap,and coagulating the soap with hydrate of alumina.

20. The method of waterproofing a calcareous cementing material whichcomprises the steps of adding to the wet cement, a solution of resinateof ammonia, and precipitating rosin therefrom by the addition thereto ofhydrate of alumina.

JUDSON A. DE CEW.

